Plug-in circuit boards having electronic components located thereon that are interconnected by printed wiring circuitry of the circuit board are widely used in the Telecommunication and Computer Industry. These types of circuit boards are oftentimes inserted in equipment mounting apparatus used to interconnect the circuit boards to form electronic systems such as telecommunication switching and computer systems. In general, the equipment mounting apparatus comprises frames having grooves located therein which receive edges of a circuit board and guide the circuit board to engage apparatus used to connect circuit boards together to form an electronic system.
The interconnecting apparatus may consist of a connector for receiving a circuit board and printed wiring circuitry for interconnecting the connector with terminals provided to terminate wiring of the equipment mounting apparatus. Printed wiring circuitry used to connect the connector with terminals of the equipment mounting apparatus oftentimes have long parallel electrical conducting paths each coupling a connector contact with a corresponding terminal. Such long parallel electrical conducting paths are generally not suitable for use in high speed data circuits of telecommunication switching and computer systems because of objectional crosstalk generated in a conductor path by data signals occurring in adjacent conductor paths.
Various designs have been developed to improve the transmission characteristics of these types of connector apparatus. For example, one connector assembly uses printed wiring circuitry to interconnect a connector with cable assemblies wherein conductor paths of the printed wiring circuitry are connected to a common ground bus and used to separate adjacent signal carrying conductor paths. A problem with this type of connector apparatus is that each signal carrying conductor path is not surrounded by shielding and a shielding discontinuity exists at the connector where the printed wiring circuitry is connected to backplane circuitry of the equipment mounting apparatus.
Connector apparatus has been mounted on a circuit board and designed to engage other connector apparatus terminating coaxial cables so that the coaxial cables may be coupled with the circuit board. However such connector apparatus is bulky in size and is not suitable for use in high density plug-in circuit board applications wherein circuit board microprocessors are required to be coupled to high density backplane pin arrays of equipment mounting apparatus.
Accordingly, a need exists for a high frequency connector for use with a circuit board to interconnect the circuit board with the backplane of equipment mounting apparatus. A need also exists for a high density and high frequency connector mounted on a plug-in circuit board to interconnect high speed circuitry of the circuit board with equipment mounting apparatus backplanes by the use of electrically shielded conductor paths.